Funds are requested as support for travel and 5 days housing and subsistence of 25 key speakers plus room and board only for 25 other speakers and participants at the 1981 Gordon Conference on Energy Coupling Mechanisms. The speakers will be selected by a group of eminent investigators in the field, and will represent major laboratories in the United States and other countries. The participants (limited because of space to 160-170) will all be active investigators in the field of bioenergetics from the U.S. and abroad, and will all have active participation in the Conference as speakers, discussants, and/or authors of poster presentations. The program will be composed of 9 sessions (3 1/2 hrs each; one session in the morning, and one in the evening except Friday evening) plus daily afternoon poster sessions. The areas covered in the 9 slide presentation sessions are: Structure of Energy Transducing Membranes, Electron Transfer Systems, Proton ATPases (2 sessions), Transport (Cations), Transport (Anions and Neutral Molecules), Biogenesis of Energy Transducing Membranes, and Energy Transduction Mechanisms and Molecules (2 sessions). The Conference has been coordinated with the programs of the bioenergetics symposia of the IUPAB/PAABS Congress, which will take place in Mexico City during the week immediately following this Conference, and overlaps have been minimized. All Conference participants receiving support will be required to stay throughout the entire program. The Gordon Conference on Energy Coupling Mechanisms consists of one work-week of total immersion, 12 hrs or more per day of contact, discussion and information exchange among 160-170 international investigators in the field of bioenergetics. Its impact in the past has been unmatched by any other domestic meeting in this area, and the number of applicants has always exceeded the available space.